1. Field of the Invention
The present invention relates to a plate-link chain, in particular for a motor vehicle drive system. The chain includes a large number of link plates hingedly connected with each other by rocker members, wherein the rocker members run transversely to the longitudinal direction of the plate-link chain and are positioned in openings in the link plates. There are curve-shaped contact surfaces located on each of the rocker members and link plates, along which contact surfaces the rocker members and link plates are in contact with each other to transmit power. There also are curve-shaped rolling surfaces on the rocker members, along which the rocker members roll on each other to transfer power. The rocker members are shaped asymmetrically in the height direction of the rocker members, viewed in a cross section running in the longitudinal direction of the plate-link chain, and the contact surfaces between rocker member and link plate are provided on upper and lower contact surface regions in the height direction of the rocker member.
2. Description of the Related Art
A plate-link chain of the type described above can be employed in a vehicle drive system. When used in a continuously variable, belt-driven conical disk transmission (CVT) as part of the vehicle transmission, the rocker members have specially shaped faces by which the tractive force is transmitted between the conical disks and the plate-link chain as a frictional force. In many other applications in vehicle drive systems the plate-link chain is a toothed chain, so that it has teeth on at least one edge, by which the tractive force is transmitted between the chain and toothed wheels. Such a plate-link chain in the form of a toothed chain can be employed in a distributor gear unit of an all-wheel-drive motor vehicle, for example, or also for bridging center distances to a differential, or also as a power transmission means in a secondary drive or for an auxiliary unit of the motor vehicle, for example.
The plate-link chain is made up in that case of a large number of link plates that are hingedly connected with each other by rocker members. The link plates can be arranged in the form of plate sets in such a manner that a plurality of link plates bounding on and adjacent to each other are penetrated by the rocker members, so that a plate-link chain results that can transmit large forces when it is under tension.
Such a plate-link chain has become known on the basis of U.S. Pat. No. 5,651,746, for example. That known plate-link chain has rocker members that rest against each other on rolling surfaces to transfer force. The radius on which those rolling surfaces are based is designated as optimal within a spacing-dependent window. The intended object of that is that the known plate-link chain will not suffer any lasting prior damage in the region of the rolling surfaces during preloading. If a tensile force is transmitted with that known plate-link chain, then the geometry of the rolling surfaces of the rocker members can result in an unfavorable distribution of forces in the region of the contact surfaces of the rocker members and the link plates, which increases the danger of the rocker members twisting in the openings of the link plates, thus resulting in stress peaks that promote premature failure of the plate-link chain.
Therefore, an object of the present invention is to provide a plate-link chain with which there is more favorable distribution of forces in the region of the contact surfaces of the rocker members and the link plates, so that the described problem is eliminated.